I´m kind of having an issue with loading in and displaying images from FAT with the new project.
Half of the graphics display correctly, the other half doesn´t. Garbled stuff all over the place.
Since that´s closely related to what you requested, I´ll only look into loading AmplituDS BGs from FAT when I fix these issues.

I won´t make any promises though. AmplituDS really needs a lot of rewriting in general, and adding another feature (which takes a day or two full-time) in a hacky way which would need to be adjusted for the rewrite doubles the work. It´d be like adding the same feature twice.

I´ll probably end up starting rewriting parts of AmplituDS when I need to take a break from the new project. And I also still need to work on (stages for) tssf´s new music. Damn busy. No time. *shakes fist at Father Time* Make time relative already instead of absolute!